Method of repressuring oil sands



J. o. LEwls nismo oil- .nsmssunxna on. sums.

Fund nov. 22,"1925 i y Nov. 12, 1929.

f It is a common practice in those iields where the initial rock ressure has' become. i 10 exhausted or so deplete as to be insiiiiicientu for forcing liquid petroleum from `the sands into the producing wells to sup ly an artifi-v l cial pressure for that pur ose. s he artificial pressure medium origina y consisting of air t 15 or natural gas is forced into a central well of a lui petroleum ahea of it .through the sands into reducing wells, the pressure me dium then eing recovered forre-use and the 20 hydrocarbon content accumulatedduring v travel of the medium through the sands being ,removed by condensation or otherwise. With` Y a system of this kind it is customary to draw ofi a part of the gases for use as fuel in the 25 explosion engine which operates the compresv sor and to replenish the supply of circulating gases with fresh air. When the fresh air is mixed with the gases it formsa combustible mixture which notinrequeutly becomes ig-v v30 nited from back-tire of the engine lightning or other causes, resulting in explosions which vcause damage to lthe equipment and injury i to workmen. y i The princi al object of the resent invention is to obviate this dangeg o explosion byA i supplying the ressure medium in separate too'lean or'too rich for ignition and may consequently be employed without danger of exploson. Y In accomplis this object I employ improved details o structure, the referred :forms of which are illustrated in e accom-` panying drawingsgjwhereim' Fig. 1 is a rspective view of an tus with whi Y emlployed.

ig. 2 is an appara? i ments of the apparatus". v

.um o. Lawrs. or Tulsa, ox'mmomassronon. nr nomi a mms, oir TULSA, onnaizoiu, a ranmnsm-eoirrosan or mm1-.r

m01) 0l' OIL My inventioii relatesl to a method of re-J the replacement of gases with atmos heric under suicent ressure to move the e with f slugs of air an gas which are respectivelyl .to near the bottom of the tank and the,

my improved method may c vertical sectioniof the gas trap and air an gas valve included as 1 application inea irqnmmaame. sensi-ire;- inem.

Fig. 3 is a longitudinal sectional view of i the air and ating lever.

- Referring Erst' to the apparatus A,

erence to the drawings:

y l' designates an ai-r well, i. the central Well i in a group to which artificial pressure medium` is supplied for feeding the other or producing wells 2. Located in suitable proximity to the wells is a compressor 3 of portable lor sta gas valve and a part of its oper- -f I tionary tvpe comprising high and low stage chambers 4 and 5 and pistons not shown) A operatable from an e lesion engine indicated grtlsie cylinders 6 an -7 and a mixing chain- Beading throughthe lower portion of theU` tank 11 is a conduit 13 also extendin centrally through the tank to about the mid e there 14, the- 3l conduit 13 having a branch I5 exterior to the of and terminating in a return bend tank, openin to atmosphere and having l.

threeway va ve 16 between the branch ang a 1 y stage compressor cylinder no tank. Cpenin from the valve 16 is a i leading to the ow P Pe l i C a Opening from the producing wells 2 are branches 9 connecting with a main return line 4. f The stem 18 of the valve 16 carries a lever 19 having a lip 20 on its free end provided i an aperture 21. Extending loosel tleou h the aperture 21 is a ro e 22 which e n ded fromabeam24onaframe25enclolf mg the tank 11 and thence the top ofthetanln.

26. e'ncl0sl`n the gas conduits 10 and 13 and their returngbends, the bell exten and the return bends gas conduits.- Fastened Ito the rope 22abovethe valve lever 19 is a wei t 28 for counterbalancing the bell 26 and or engaging with the valve lever to rock the'latter w en by a volume o gas flowing therento fromtlie over pulleys or guide ro ers 23 sus ss centrally timings i s aeafmmaim aawithinthank isanbiilm Pe the bell iselevated 'aan l .nl interior. With t arrangement gas l producing wells. Below` the valve lever the rope 22 is' irovided v'thia butto 29tlf1orxi v' 'W e wgfngdolnn f gafm.. :da mitted tothe bell raises the latter until the weight 98 shifts the valve lever in the con-` -escape o y duit 'ieadin to the compressor, openin the conduit tot e assage of gas admitted m 1 the bell throug the return bend in pipe 13.-

- As gas. escapes from the bell, the latter de-. scends by gravity liftin the button on the end of the wpe 22 until t e latter engag the Y valve lever. shifting the lever to close oli' l1|; the gas supply and admit air to the pi 17 throu h the branch 15.` It is apparent, t erefore, at gas and air are admitted to the compressor separately and not in such relation `as to produce a combustible mixture.

m The low stage compressor cylinder 4 is se 11 and three-way connected with a big-l stage cyhnder 5 by a sipe 30 and leading m the high stage cyliner is a pi 31, coiled at 32 to form a condenser an communicatin with a scrubber 'u tank 38 wherein condensa le content of the compressed fluid is collected. Opening from `the top of the tank 33 is the pipe 34 which leads to the air well L Opening from the pipe 13 between the tank valve 16 is a branch A35 leading to the mlxer 8 of the as engine for supplying gas returned 'from t e-wells to the for use as a fuel therein. .T

Eni

as the aid ofthe apparatus described, assuming'the ap aratus-to be assembled and connected with 'the wells as above stated, when the engine is in o ration air l'is' initially drawn through the ow stage cylinder, comressed therein and in the high stage cyliner and passed through the pule 31, tank 33 and pipe 34 to the air well in t e field. The air bei forced through the sands. drives .the liqui along with it to the producing wells from which the oil may be recovered in accordance with common ractice. As the air travels through the san it becomes saturated with lighter constituents of the petroleum contained within the sand so that when it leaves the producing wells it constitutes a combustible vapor or saturated When this vapor or gas is delivered to the bell of the gastrap itaccumulates therein until its pressure is suicient-to lift the bell and shift the4 valve in the compressor supply conduit. -When the valve is shifted the aar supplied to the compressor is cut ofi' and the gas su ply o e the gas and vapor then aing om thpeenbe into the compressor an from there circulated to the air well1 as was the atmos- ,.pherie'air heretofore mentioned'. As the gas escapes' from the bell the'latter descends by until the three-way valve is again when the pwdssii

tho ir Supply racticing my improved method withl gassupplyisshuto and alternate of gasand air are separately l' y admitted to the compressor and delivered in separate slugs intothe air well, at no. time co-niingling to produce a combustible or ex.- plosive mixture.

In this way, am enabled to-empl'oy air and gas for'use as artificial pressure medium in the stimulation of flow of inert oil from the Y f L sands and increase-or renew production in elds which have been abandoned or have decreased in production tosuch .an extent as to be'un roiituble.

tersPatentiszp Y 1. The method of repressuri-ng oil sands `consist-ing of delivering char es of air and gas alternately to the sands un er pressure.

if; alternately to the sands through thesame e under pressure.

2. .The method of repressuring oil` sands y consisting of del-iveringeharges of air and What claim and desire to secureby Let# i a. The method f repessuringeil sagas. La

consisting of delivering a continuous dow of pressure medium consisting of alternate volumes of air and gas to the sands. A

4. The method of repressuring oil sands .consisting of compressing air and gas se arately and delivering the air and -gas to t e sands under pressure in, alternate volumes ,and in continuous iow.

5.' The method of repressa oil sands consisting of supplying gas an air'alternately to a compressor, compressing the gas air separate y in the compressor and su plynlg the compresed gas and air to e san 6. The method of repressuring oil sands consisting of storing gas, admitting said gal and air alternately to a com ressor, compressingthe medium admitte to the compreor, delivering the medium under pressure to the sands, and controllin selection iol of the medium to be compressed y volume n A y of the stored 7. The me od of repressuring consisting of supplying gas an air alternately to a compressor, compr the medium supplied to the compressor,r f 'ver ing said medium to the sands, and controlling se ection of the medium supplied to the compressor by volume of the ,gas available at the point of sup ly.

8. The method) of oil sands from a produein well, supplying sai and air alternatey to a com ressor-,compressing the medium suppli to the compressor, delivering said medium to the sands :Y under pressure, Vand eecting selection of adcordingto volume of the conn In y whereof lmy repress'uring oil sands-- vconsisting of recovering and confiningv gas' gas mission of gas or air to the com ressor ae-r 

